Modern farmers strive to improve the management of increasing amounts of farm acres. Improving management requires farmers to be able to quickly prepare the soil for each season""s farming operations. This haste has driven the need for more efficient and larger farming equipment.
Implements such as harrows, packers, or combined harrow-packers were some of the earliest implements to be made with widths exceeding sixty feet in the field operating position. As tractor horsepower has increased over time, larger tillage implements have been made available. These larger implements require a mechanism for compactly folding the implement for practical and safe transport over the highway. U.S. Pat. No. 4,821,809, patented by Summach et al., discloses a convenient mechanism for such folding.
The conventional method of folding tillage implements is by folding wing sections along forward aligned axes such that the wings are folded to a generally upright position. Double folding wing sections may have outer sections that fold inwardly and downwardly from the ends of inner wing sections in five section winged implements. In the case of these conventional wing implements, the minimum implement width that can be achieved by such folding is limited by the width of the center section. As a result, road transport may still be somewhat restricted as these implements often exceed twenty feet or more in transport width.
Road transport standards in North America are beginning to follow the standards set in Europe in which maximum road transport widths and heights for agricultural implements are being defined. Large implements that have conventional folding wing sections are not able to be folded such that they fall within width and height limits that may be generally 3 meters wide and 4 meters high. Some U.S. states have adopted transport width limits of 13.5 ft.
Forward or rear folding implements provide some relief with respect to such transport limits. However, implements must also be made to function with the accurate seeding ability that conventionally folded implements have become capable of. Although some rear or forward folding multibar tillage implements have been developed, they do not demonstrate the accurate depth control required for farming operations.
One problem is that a tillage-packer combination for drill seeding requires the gang supporting tillage elements to be maintained parallel to the ground through a range of adjustable operating levels. The drawbar disclosed in Summach ""809 raises or lowers the first attached gang of elements in a rotatable manner through its field and transport ranges of motion. A level manner of height adjustment is required for tillage elements.
Another problem that must be overcome for compact folding is the avoidance of the packer elements of the second gang striking the tillage elements of the first gang when raised to the transport position. If compact folding is not required, then the downward rotation of the suspended second gang may be limited so as not to impact the elements of the first gang. But when compact folding is desired, the elements of the second gang are in direct alignment with the ground elements of the first gang so that alignment is achieved.
It is an object of the invention to provide a compact folding multibar implement capable of accurate depth control in field working positions.
It is another object of the invention to provide a compact folding implement capable of being configured either as a multibar implement or as a single bar implement for row crop applications, thereby providing economy in manufacturing.
One key advantage of this style of folding is that for a harrow-packer combined implement, the packers are pulled inward toward the implement frame substantially before they are lifted from the ground, which significantly reduces the torsion required of the toolbar or frame elements in order to produce sufficient lifting force to effect compact folding.
The invention provides a farm implement frame which includes multiple elongated generally planar and horizontal frame sections to which individual ground working tools may be mounted. The frame sections extend transverse to the direction of travel when in the working position and include spaced apart members extending generally in the direction of travel when in the transport position. A hitch member connects the implement to a tractor or other motive source at the center of the frame sections. Each frame member includes an inner end and a distal end connected together at their respective inner ends by a main pivotal connection adjacent the forward members. The pivotal connection defines a generally vertical axis so that the inner ends of the frame sections abut one another in the working position. The frame sections are separately supported above the ground by a first set of wheels adjacent the inner end of the rearward members. The frame sections are also supported by the hitch members and by a second set of wheels adjacent to each distal end, so as to remain generally parallel to the ground in the working position. Preferably one set of wheels caster and one set of wheels is steered.
It is an advantage of the invention that the combination of a set of castering wheels at the outer end of the frame assemblies and a set of steered wheels at the inner end of the frame assemblies provides enhanced stability.
The invention further provides hydraulic cylinders operable between the frame sections to move the sections between the working position and the transport position. A tongue member extends rearwardly of the pivot connection to anchor the hydraulic cylinder for moving the frame sections.
The invention also provides a pair of hydraulic cylinders connected to the rearward members of the frame sections. The frame sections include upper and lower members adjacent their respective inner ends.
The invention further provides hitch members which are pivotally connected together at a forward end adjacent the tractor and pivotally connected to the frame sections about a generally vertical axis. The hitch members include locking means operable in the transport position to maintain the frame sections generally parallel to the direction of travel. The hitch members have no separate wheel support.
The invention also provides rockshafts pivotally attached to respective rearward members for movement about an axis parallel to and rearward of the frame section when in the working position. The rockshafts are adapted to carry tool sub-frame sections pivotally attached to a respective rockshaft for motion between a generally horizontal working position and a generally upright transport position. Tool hydraulic cylinders between the rockshafts and the tool sub-frame sections operate to control their respective relative rotational movement about the rockshaft to accommodate undulations in the ground when in the working position.
The tool sub-frames may be shaped as a parallelogram to extend at a substantial non-right angle to the rockshaft and carry wheeled support members rearward of the tool sub-frames when in the working position. The wheeled support members include a connecting apparatus between the tool sub-frames and the rockshaft to control their respective positions. The connecting apparatus is operable to provide a working position in which each of the tool sub-frames are substantially parallel to and spaced above the ground by a variable amount and is further operable to reduce the height of the wheel support members above the ground when the tool sub-frames are raised to a substantially vertical position for transport.
These and other objects, features, and advantages are accomplished according to the present invention by providing a frame for a tillage implement including a pair of opposing frame sections pivotally connected to a central kingpost for a folding movement between a transversely extending working position and a longitudinally extending transport position. The frame sections have mounted thereto a number of tool sub-frames carrying ground engaging working tools. The tool sub-frames are pivotally movable relative to a rockshaft carried by the frame sections so as to be rotatable between a lowered operative position and a generally vertical raised non-working position. The frame sections are connected at the inner end to the kingpost so that the main frame members abut when placed in the working position. Each frame member is supported by a pair of wheel assemblies at the inner and distal ends respectively. The inner wheel assemblies of each frame section is steered by a link connecting the wheel spindle to the hitch member to control the orientation thereof.